# -*- coding: utf-8 -*-
"""
Created on Thu Oct 26 09:06:55 2017

@author: Luther
"""


def countfeq(s):
    s_list = s.split('/')
    [s_list.remove(item) for item in s_list if item in '，。！”“']
    s_dict = {}
    for i in s_list:
        s_dict[i] = 1
    try:
        s_dict.pop('')
    except:
        pass
    return s_dict


if __name__ == "__main__":
    s = input()
    s_dict = countfeq(s)
    print(len(s_dict.keys()))
